1. Field of the Invention
The invention relates to cosmetic and dermatological preparations in the form of capsules comprising an envelope which is solid, semisolid and/or dimensionally stable and consists essentially of waxes, emulsifiers, natural and/or synthetic polymers and/or mixtures thereof, and to the method for their production. Furthermore, the invention relates to a capsule with a filling consisting of one or more solid, semisolid, pasty and/or liquid ingredients. Optionally, the envelope may additionally comprise water and/or polyols.
The property of the envelope is characterized in that it                melts upon rubbing and/or distributing the preparation on the skin and/or the hair and/or becomes completely or partially liquid due to shear forces        and/or it dissolves in the filling and/or the skin sebum lipids or as a result of mixing internal phase and enveloping materialand is thus no longer perceptible for the user as a separate constituent of the preparation besides the filling.        
2. Discussion of Background Information
The prior art discloses pharmaceutical capsules, for example soft and hard gelatin capsules, which consist of an envelope of gelatin and glycerol, and sometimes dyes, and a liquid, pasty or particulate filling. The method of producing these capsules known for many years takes place, for example, in accordance with the so-called rotary-die system (Seifen-Öl-Fette-Wachse, Vol. 113; No. 3/1987, page 67 ff). These gelatin capsules dissolve when swallowed in the gastrointestinal tract and release their ingredients. Since it is directly possible to produce capsules in different sizes and shapes, use is limited not just to peroral application forms (Rudolf Voigt, “Pharmazeutische Technologie” [Pharmaceutical Technology], Deutsche Apotheker Verlag, Stuttgart, 9th edition (2000), p. 543ff). Oral absorption can be achieved through suckable capsules. They are hollow on the inside and have a wall which is three times thicker than that of other capsules. The active ingredient is incorporated here in the gelatin envelope. A further example is nitroglycerol chewable capsules (bite-through capsules), which likewise allow rapid absorption of the active ingredient via the oral mucosa. Furthermore, individually dosed medicaments can be applied after puncturing or cutting the tubular ointment capsules by squeezing out the contents (percutaneous application of nitroglycerol heart ointment).
From the food sector, pralines, which comprise liquid or pasty ingredients in a dimensionally stable chocolate coating, for example, are known. The coating melts during sucking or biting through in the mouth or after swallowing.
In the cosmetics sector, the so-called bath beads are known whose envelope, e.g. made of gelatin, dissolves in hot or warm bathwater without leaving a residue and releases its contents, for example surfactant preparations, emulsions, lipids, dyes and/or perfumes, into the bathwater. Since the envelope consists of gelatin, the product must not contain water, otherwise the envelope would soften during storage.
A second group of cosmetic capsules covers all products for which the envelope represents only a container for the single dose and use and whose envelope is left behind following use. A disadvantage with this is that the envelope which is left behind is troublesome and in addition has to be disposed of.
Numerous cosmetic and/or dermatological active ingredients are unstable toward certain influences such as moisture, low or high pH values and oxygen or light. There has therefore been no lack of attempts to remove the specified undesired environmental influences from such active ingredients in such a way that the active ingredients are nevertheless released upon application. One way of achieving this aim 1s the microencapsulation or nanoencapsulation of active ingredients. The encapsulation material as carrier system for the active ingredients allows them to be incorporated into suitable preparations in a form protected against environmental influences without the user being able to perceive the capsules during product application.
The aim of such an encapsulation is, for example, to produce wax particles containing active ingredient in the micrometer range (1-250 μm) which can be incorporated into common pasty or liquid cosmetic preparations. It is hitherto not known to produce, store and topically use these microcapsules as an independent cosmetic preparation. DE 10210449 discloses wax-coated capsules which have a content of active ingredient. These capsules are produced by means of a so-called fluidized-bed process, meaning that, at most, capsules measuring 200 μm can be produced.
There are a number of approaches for encapsulating cosmetic active ingredients. For example, the liposomal encapsulation of medicaments, which is intended to lead to a slow release of active ingredient, is known. These are essentially spherical vesicles containing active ingredient and surrounded by phospholipids or other amphiphilic agents, the so-called liposomes. The long-term stability of such structures, however, is poor.
Nanoparticles are solid particles with particle sizes of from 20 to 500 nm. Sometimes, larger particles with diameters up to 1000 nm are also regarded as being nanoparticles. Particles of this type generally consist of polymers and have cavities or form a envelope so that guest molecules stay themselves on the inside, these molecules being enclosed or adsorbed. These guest molecules are then slowly released upon application of the nanoparticle-containing product. Solid lipid nanoparticles, which comprise active ingredients distributed within a matrix made of solid lipids behave in a similar way. The size of the particle is comparable with that of nanoparticles.
Numerous methods are known for encapsulating pharmaceutical or cosmetic active ingredients for controlling active ingredient release or the stable incorporation in preparations.
European patent application EP 1064911 or EP 1064912 discloses microcapsules comprising active ingredient and having a diameter of from 0.1 to 5 mm which are obtained by preparing a matrix from gel formers, chitosan and active ingredient, and adding this dropwise to aqueous solutions of anionic polymers. In so doing, a membrane forms from chitosan and anionic polymer and surrounds the active ingredient solution. These microparticles are then in turn used as constituent of customary cosmetic preparations. General information regarding encapsulation techniques with chitosan can be found in Journal of Microencapsulation 14, pages 689-711 (1997).
Mostly lipophilic active ingredients encapsulated in lipid particles are known per se to the person skilled in the art. For example, EP 167825, DE 100 59 668, DE 199 45 203, EP 0934743, WO 94/20072, WO 00/10522 and WO 00/67728 describe lipid particles charged with active ingredient. However, these documents were unable to solve the problem of providing capsule-like preparations with enclosed liquid, pasty or solid cosmetic ingredients and which can be prepared, stored and applied topically as an independent cosmetic preparation.
DE 19852262, DE 9321186 and CH 692968 disclose methods of producing confectionery, in particular chocolate articles, by the so-called one-shot, frozen-cone or cold-stamp method.
The methods described therein are concerned exclusively with the production of chocolate articles, pralines.
It is an object of the present invention to provide a cosmetic preparation which is in the form of a solid, semisolid or dimensionally stable capsule, is thus individually portionable and can be distributed as a whole on the skin. In particular, it is the object of the present invention to provide a cosmetic preparation which constitutes a novel cosmetic product form and offers the user a novel application experience and broadens the application spectrum of skin care and/or hair care products.